#region Copyright & License Information
/*
 * Copyright (c) The OpenRA Developers and Contributors
 * This file is part of OpenRA, which is free software. It is made
 * available to you under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version. For more
 * information, see COPYING.
 */
#endregion

using System;
using System.Linq;
using OpenRA.Mods.Common.Traits;
using OpenRA.Server;
using OpenRA.Traits;

namespace OpenRA.Mods.Common.Lint
{
	sealed class CheckDefaultVisibility : ILintRulesPass, ILintServerMapPass
	{
		void ILintRulesPass.Run(Action<string> emitError, Action<string> emitWarning, ModData modData, Ruleset rules)
		{
			Run(emitError, rules);
		}

		void ILintServerMapPass.Run(Action<string> emitError, Action<string> emitWarning, ModData modData, MapPreview map, Ruleset mapRules)
		{
			Run(emitError, mapRules);
		}

		static void Run(Action<string> emitError, Ruleset rules)
		{
			foreach (var actorInfo in rules.Actors)
			{
				// Catch TypeDictionary errors.
				try
				{
					var visibilityTypes = actorInfo.Value.TraitInfos<IDefaultVisibilityInfo>();
					var count = visibilityTypes.Count;

					if (count == 0)
						continue;
					else if (count > 1)
						emitError(
							$"Actor type `{actorInfo.Key}` defines multiple default visibility types: " +
							$"{string.Join(", ", visibilityTypes.Select(vis => vis.GetType().Name))}.");
					else
					{
						var vis = actorInfo.Value.TraitInfoOrDefault<HiddenUnderShroudInfo>();
						if (vis != null && vis.Type == VisibilityType.Footprint)
						{
							var ios = actorInfo.Value.TraitInfoOrDefault<IOccupySpaceInfo>();
							if (ios == null)
								emitError(
									$"Actor type `{actorInfo.Key}` defines VisibilityType.Footprint in `{vis.GetType().Name}` " +
									"but has no IOccupySpace traits.");
							else if (ios.OccupiedCells(actorInfo.Value, CPos.Zero).Count == 0)
								emitError(
									$"Actor type `{actorInfo.Key}` defines VisibilityType.Footprint in `{vis.GetType().Name}` " +
									"but does not have any footprint cells.");
						}
					}
				}
				catch (InvalidOperationException e)
				{
					emitError($"{e.Message} (Actor type `{actorInfo.Key}`).");
				}
			}
		}
	}
}
